Fuse construction



Sept' 9, 1941- w. o. SCHUL-rz v 2,255,300

F U s E C O N S T R U C T I O N y Filed Aug. 14, 1939 2 Sheets-Sheet 2 Y l v n INVENTOR. h//zz/AM 2 5am/fz Patented Sept. 9, 1941 russ CONSTRUCTION William .0. Schultz, South Milwaukee, Wis., assignor to Line Material Company, South Milwaukee, Wis., a corporation of Delaware Application August 1'4, 1939, serial No. 290,033

i Claims.

This invention relates to a fuse construction. Objects of this invention are -to provide a housed type of fuse in which the door protects the inside of the housing at all times even after the fuse has blown, and to provide such a construction in which the fuse tube moves out of circuit and the door moves to an angular position without moving completely away from thehousing, thereby still acting as a door to prevent entrance of snow or rain and protecting the inside of the housing.

Further objects are to provide a housed type of expulsion fuse in which the fuse is supported by a lever from the lower support and is both pivotally and slidably joined to the lever so that the lever and fuse together constitute a link structure allowing the lower end of the fuse tube to move outwardly and the link structure to elongate itself Without detaching the upper end of the fuse tube from the upper stationary contact.

Further objects are to provide a fuse construction in which the fuse tube and door form an assembly and are pivotally supported by a double hinge construction from the lower support and are spring. urged outwardly, and in which a contact linger is spring urged into contact engagement with the lower terminal, said contact ringer maintaining contact with the lower terminal for a material length of time while the fuse tube is moving outwardly to thereby allow the tube to clear itself prior to the breaking of the connection between the contact finger and the lower terminal, and to provide a construction whereby a portion of the link mechanism acts as a stop tc limit the motion of the contact :finger when may be readily detached from the housing for refusing and after refusing, may be again 'positioned ,for pivotal support from the housing and may then be rocked into operative position.

An embodiment of the invention is shown in 5 the accompanying drawings, in which:

Figure 1 is a view partly in section showing the fuse in closed position.

Figure 2.is a view similar to Figure i showing the position of the parts after the fuse has blown.

`(ci. zoo-114) towards the lower portion of the door` and fuse assembly with the door and fuse assembly removed from the housing.

Referring to the drawings,'it will be seen that the device comprises a housing i of porcelain or other suitable insulating material and a door 2 of a phenolic condensation compound or other suitable material, such door being provided with an eyelet or handle portion 3. The housing is adapted to be positioned in either a vertical position or in a slanting position with the upper end projecting outwardly beyond the lower end and is carried from 'a suitable support not shown.

The housing is provided with upper and lower stationary contacts having terminal portions i and 5 respectively, adapted to receive line wires which pass through apertures in the side walls not shown. The upper terminal also includes a contact brush 6 and a pair of resilient, outwardly extending arms l which form a U-shaped structure and which have outer, downwardly extending end portions 8 provided with downwardly and outwardly slanting cam faces 9.

The lower stationary contact includes the terminal portion 5 and a iiat contact face I 0 presented towards the front of the housing. A suitable barrier I i is located between the upper and lower terminalsfin accordance with the usual construction, and the lower portion of the box l or housing has an open portion l2 directly below the lower open end of the fuse tube t3. The lower supports it are rigidly carried by the ho er ing and may be supported directly from the haca wall of the housing or from an extended portion of the back wall as shown at l5. These lower supports i4 are provided with hook portions it which removably receive the outwardly projecting trunnions Il of a lower supporting lever i8.

The lever I8 may be of somewhat channel shape as shown and may have a transverse web I9 extending to approximately its upper end. The upper end of the lever is in the form of spaced, upwardly extending arms 20 which are slotted as indicated at 2l and are each provided with outwardly projecting stops or lingers 22.'

I'he lower end of the lever is provided with an abutment 23 which normally is held in engagement with the fuse tube by means of the fuse link as shown in Figure 1.

The lever is provided with a threaded shank 24 and a thumb nut 25 for clam-ping the flexible leader 26 of the fuse link in place.

The fuse link may be of any suitable type. For example as shown, it may have the flexible Figure 3 is a detail looking from the inside 55 leader 26 and a reduced fusible portion 21 and voccurs within the fuse tube.

an upperv button-head which is clamped between the removable screw cap 28 and the upper terminal portion 29 of the fuse tube. 'I'hls upper terminal portion 29 is provided with a forwardly projecting extension 38 that normally bears against the inner face of the door. It is provided with a attened, downwardly extending portion 3| on its rear side against which the spring brush 6 bears. The door is providedwith a pair of outwardly bowed cam members 32 which are provided with the spreader portions or cam portions 33, see Figure 2, which are adapted to spread the springy upper arms I when the door is manually pulled open.

' The upper terminal 29 of the fuse tube is provided with pins 34 which project outwardly on opposite sides and which are normally in engagement with the cam faces 9 of the downwardly extending extensions 8 ofthe arms T. -However, when the door is manually pulled open, these cam members 33 spread the portions 8 of the arms I and allow the pins 34 to pass outwardly from between the spring arms 'I. The construction is quite similar to that shown in the Schultz and Steinmayer Patent No. 2,029,593 of February 4, 1936.

The fuse tube I3 is provided with a block or member 35 rigidly secured thereto and pivotally joined to a pair of inwardly projecting arms 36 carried by the door. The pivotal connection is aiiorded by the screw or bolt 31. The member 35 has a pair of spaced, downwardly extending arms 38 which terminate in inwardly and downwardly slanting arms v39 which constitute stops for engagement with the web I 9 of the lever I8 to limit the outward motion of the fuse tube and door assembly, as shown in Figure 2, after rupture of the fuse link.

The arms 38 carry a pivot pin QU which is positioned within the slots 2| in the arms 20 of the lever I8 and'which also pivotally carry a contact finger d I such contact finger being provided with a pair of downwardly extending arms 42 through which the pin Il!) passes to thus pivotally support the contact arm 4I.

This contact finger 9| has a wide bearing face that bears directly against the face IU of the lower stationary contact, as shown in Figure 1, and is provided with a shouldered portion s3 which is normally positioned above the ngers 22 of the lever I8, as shown in Figure 1.

A spring |54 is loosely coiled about the pin il@ and urges the contact finger or lever 4| in a counterclockwise direction, as viewed in Figures 1 and 2. If desired, the contact nger M may be provided with a strengthening rib on its upper side, but its contact face is extended transversely and has a wide bearing contact with the face IQ of the lower terminal.

'I'he door is provided with a spring A15 which bears against the lower portion of the fuse tube and tends to rock the fuse tube in a clockwise direction about the pivot pin or screw 37 to thereby hold the stop 3|] at the upper contact of the fuse tube against the door 2.

Assume that the parts are in the operative position as shown in Figure 1, and that an overload occurs. The fuse link is ruptured and the lever I 8 withdraws any remaining portion of the fuse link, in addition to the expulsion action that The lower end of the fuse tube and door assembly start to rock outwardly and the contact nger 4I maintainsl contact with the contact face I of the lower stationary contact for a material length of time during the early portion of the outward rocking of the lower end of the fuse tube and door assembly, thereby allowing adequate time for the tube to clear itself even under light overloads.

The fuse tube and door assembly are urged towards outward rocking motion by means of the upper spring brush 6 and the spring urgedcontact nger 4I, gravity also assisting in this operation when the device is mounted in a slanting position. The shoulder 43 of the spring urged contact finger bears against the stops 22 iof the lever I8 and urges the lever downwardly with ref erence to the fuse tube, in addition to the action of the upper spring brush 6, thus urging the fuse tube and door assemblytowards the position shown in Figure 2. The pin 40 freely slides in the slots 2| of the lever I8.

It is to be particularly noted that after the fuse tubeand door assembly has moved to its slanting position which it occupies after rupture of the fuse link, the contact finger 4| is out of contact with the lower contact, see Figure 2.

This construction therefore provides an extensible linkage mechanism constituted jointly of the slotted lever I8 and the fuse tube, such jointed linkagev construction being held at its upper and lower ends but free to pivot about such ends to the position shown in Figure 2, the extensibility of the linkage construction permitting such outward motion of the lower end of the fuse tube and doorassembly However, the outward motion of the parts is arrested when the lingers 39 engage the web I9 of the lever I8 as shown in Figure 2, and thus the door is prevented from opening completely and exposing the interior of the housing. Instead it forms an outwardly slanting snow shed or rain shed and thus protects the interior of the housing. However, the fuse tube is taken out of circuit, for connection with the lower stationary contact has now beenafter a new fuse link is substituted for the burned fuse link and the operator then rocks the contact nger Ill upwardly in a clockwise direction about the pivot pin 40 and thereafter moves the lever I8 upwardly to the position shown in Figure 1 and attaches the flexible leader to the lever by means of the thumb nut 25.

The operator then releases the contact linger ill and such ringer can move inwardly a slight distance due to the slight spacing of the shoulder 43 from the stops or fingers 22 of the lever I8 as shown in Figure l. He then replaces the trunnions in the hooks I6 and rocks the door to closed position. The contact iinger 4I then yieldingly and iirmly engages the face I0 of the lower sta,- tionary contact and the cam members 33 spread the portions 8 of the latch 'I and allow the trunnions to pass between the iingers 8, the ngers 8 thereafter moving towards each other and the pins 34 being then positioned rearwardly of the downwardly slanting faces 9. The spring brush 6 yieldingly and rmly engages the portion 3| of the upper contact on the fuse tube and urges the fuse tube and door assembly outwardly to its iinal position as shown in Figure 2. When the fuse tube and' door assembly have moved outwardly as shown in Figure 2, the contact finger has moved completely away from the lower stationary contact and the lower supports I4 are electrically dead.

It will be seen that a novel form of fuse construction has been provided in which advantage is taken of the idea. of taking the fuse tube out oi circuit after blowing by interrupting the circuit connection from the lower stationary contact to the lower contact oi the fuse tube, but in which the door is not allowed to drop completely open but stays in such position as to adequately protect the interior of the housing.

It will also be seen that the fuse construction is eective in its operation and provides-a positive interruption of the circuit upon either large or small overloads, and under either condition withdraws any remaining portion of the fuse link.

Although this inventionhas been described in considerable detail, it is to be understood interior of said housing after said fuse link has a door for said housing, a fuse tube secured to that such description is intended as illustrative rather than limiting, as the invention maybe variously embodied and isvto be interpreted as claimed.

I claim:

l. A fuse construction comprising a first and second stationary contact, a support, a fuse tube and lever 'assembly constituting jointly link mechanism, said assembly being movably held by said first stationary contact and pivoted to said support and having a portion movable outwardly intermediate said ilrst stationary contact and support, a movable contact carried by said link mechanism normally engaging said second stationary contact and movable outwardly with reference to said second stationary contact, a fuse link within said fuse tube normally restraining the outward motion of said link mechanism and electrically joining said stationary contacts through the agency of said movable contact, and a stop normally out of engagement with said lever and coming into contact with said lever when said fuse link is ruptured.

2. A fuse construction comprising a housing having an upper and a lower stationary contact and having a lower support, a fuse tube having upper and lower contacts engaging the upper and lower stationary contacts respectively, a fuse link within said fuse tube joining the upper and lower contacts of said fuse tube, a lever pivotally mounted on said support and on said fuse tube and being normally restrained by said fuse link, said fuse tube being movable outwardly adjacent its lower portion upon rupture of said fuse link to move the lower contact of the fuse tube out of engagement with the lower stationary contact, and means .for limiting the outward motion of said fuse tube to maintain contact between the upper contact of said fuse tube and the upper stationary contact.

3. A fuse construction comprising a housing having an upper and a lower stationary contact,

`a fuse tube and door assembly, said fuse tube having an upper contact normally movably connected to the upper stationary contact and having a lower Contact normally engaging the lower stationary contact, a support carried by said housing, a lever pivoted on said support and pivoted to said fuse tube, a fuse' link normally electrically connecting the upper and lower contacts of said fuse tube and restraining said lever against motion with reference to said fuse tube, the lower portion of said fuse tube and door assembly and the lower contact of said fuse tube being movable outwardly upon rupture of said fuse link, and means carried by said fuse tube and normally out of contact with said lever for limiting the outward motion of said fuse tube and door assembly, whereby said door shields the (iii said door, said housing having -upper and lower stationary contacts and said fuse tube having an upper and a lower lcontact normally engaging the upper and lower stationary contacts, a fuse link within said fuse tube electrically connecting the upper and lower contacts of said lfuse tube, and mechanism normally restrained by said fuse link for moving the lower portion of the fuse tube and door outwardly while maintaining the upper portion of the door in close relation to said housing and for limiting the outward motion oi said door, said mechanism moving the lower contact of said fuse tube out of engagement with the lower stationary Contact.

5. A fuse construction comprising a housing having stationary upper and lower contacts, a

fuse tube and door assembly movably carried by said assembly including a contact movable away from at least one of said stationary contacts when said fuse link has been ruptured and said assembly is held in slanting position.

6. A fuse construction comprising a housing having upper and lower stationary contacts, a fuse tube and door assembly whose lower portion is movable outwardly with reference to said housing while the upper portion remains adjacent said housing to cause said assembly to occupy a slanting position with reference to said housing, mechanism for guiding and moving said assembly to the slanting position and holding said assembly in the slanting position, said assembly having a movable contact normally engaging the lower stationary contact and moving away from the lower stationary contact when said assembly moves to the slanting position, and a fuse link within said fuse tube normally restraining said mechanism. and electrically connecting the upper stationary contact with said movable contact.

7. A fuse construction comprising a housing having stationary upper and lower contacts and having a lower support, a fuse tube and door assembly, said ruse tube having an upper contact normally engaging said upper stationary contact and having a lower contact normally engaging the Y lower stationary contact, a lever pivoted on said support and slidably and pivotally connected to said fuse tube for guiding the lower end of said fuse tube and door assembly outwardly with reference to said housing while the upper end of said fuse tube and door assembly remain in close proximity to said housing and for moving the lower contact of said fuse tube away from said lower stationary contact, a fuse link normally restraining said lever and electrically connecting the upper and lower contacts of said fuse tube, and means for limiting the outward motion oi said fuse tube and door assembly while the upper portion of said assembly remains in close proximity to said housing.

8. A fuse construction comprising a housing having stationary upper and lowex` contacts and having a lower support, a fuse tube and door assembly, said fuse tube having an upper contact normally engaging said upper stationary contact and having a lower contact normally engaging the lower stationary contact, a lever pivoted on said support and slidably and pivotally connected to said fuse tube for guiding the lower end of said fuse tube and door assembly outwardly with reference to said housing while the upper end of said fuse tubevand door assembly remain in close proximity to said housing and for moving the lower contact of said fuse tube away from said lower stationary contact, a fuse link normally restraining said lever and electrically connecting the upper and lower contacts of said fuse tube, and means for limiting the outward motion of said fuse tube and door assembly while the upper portion of said assembly remains in close proximity to said housing, said lower support being electrically dead after outward motion oisaid assembly.

'9. A fuse construction comprising a housing having stationary upper and lower contacts, a fuse tube having at least a lower Contact normally engaging the lower stationary contact, a one piece door forming an assembly with said fuse tube, mechanism for restraining the upper end of said door and fuse tube assembly from outward motion and for moving the lower end of .said fuse tube and door assembly outwardly to cause said assembly to assume a slanting position, and a fuse link electrically connecting the upper stationary contact and the lowercontact of said fuse tube and normally restraining said mechanism, said mechanism including a stop permanently carried by said fuse tube and holding said assembly in the slanting position after rupture of said fuse link.

10. A fuse construction comprising'a housing having upper and lower contacts and a lower support, a fuse tube and door assembly, a lever -pivoted upon said support and having a slotted upper end, a pin carried by said assembly and located within the slotted upper end of said lever, a spring urged contact nger pivotally carried by said assembly and normally engaging the lower stationary contact, saidl fuse tube having an upper contact normally restrained against outward motion by the upper stationary contact, said upper stationary contact including spring means urging said fuse tube and door assembly outward, means limiting the rocking motion of said lever relative to said fuse tube and preventing said fuse tube from disengaging the upper stationary contact, and a fuse link connecting said contact nger and the upper contact of said fuse tube and restraining said lever, said lever having a stop normally limiting the outward motion of said contact finger when said fuse link is intact and moving out of the way of said contact linger upon rupture of said fuse link.

11. A fuse construction comprising a casing having upper and lower stationary contacts and having a lower support separate from said lower stationary contact, a fuse tube and door assembly, said fuse tube having a fuse link therein normally electrically connected to said upper stationary contact, a contact linger normally engaging said lower stationary contact and electrically connected to said fuse link, a lever pivoted upon said lower support and pivoted to said fuse tube for moving the lower portion of the fuse tube and door assembly outwardly a limited distance uponl rupture of the fuse link, said fuse linknormally restraining the movement of said lever,l means for holding the upper portion of said `luse tube and door assembly to said casing after said lever has moved the lower portion of said assembly outwardly, and a stop rigidly carried by said fuse tube and limiting the rocking motion of said lever relative to said fuse tube.

l2. A fuse construction comprising a casing having upper and lower stationary contacts and having a lower support separate from said lower stationary contact, a fuse tube and door assembly, said fuse tube having a fuse link therein normally electrically connected to said upper stationary contact, a contact finger normally engaging said lower stationary contact and electrically connected to said fuse link, a lever pivoted upon said lower support and pivoted to said v l fuse tube for moving the lower portion of the fuse tube and door assembly outwardly a limited distance upon rupture of the fuse link, said fuse link normally restraining the movement of said lever, and means for holding the upper portion of said fuse tube and door assembly to said casing after said lever has moved the lower portion of said assembly outwardly, said contact iinger moving away from said lower stationary contact due to the movement of the assembly outwardly the said limited distance.

13. A fuse construction comprising a casing having upper and lower stationary contacts and having a lower support separate from said lower stationary contact, a fuse tube and door assembly, said fuse tube having a fuse link therein normally electrically connected to said upper stationary Contact, a contact inger normally engaging said lower stationary contact and electrically connected to said fuse link, a lever pivoted upon said lower support and pivoted to said fuse tube for moving thev lower portion of the fuse tube and door assembly outwardly a limiteddistance upon rupture of the fuse link, said fuse link normally restraining the movement of said lever, and means for holding the upper portion of said fuse tube and door assembly to said casing after said lever has moved the lower portion of said assembly outwardly, said contact nger moving away from said lower stationary contact and said lower/support being electrically dead upon/movement of the assembly the said limited distance.

14. A fuse construction comprising a housing having an upper and a lower stationary contact and having a lower support, a fuse tube having upper and lower contacts engaging the upper and lower stationary contacts respectively, a fuse link within said fuse tube joining the upper and lower contacts of said. fuse tube, a lever pivotally mounted on said support and on said fuse tube and being normally restrained by said fuse link, said fuse tube being movable outwardly adjacent its lower portion upon rupture of said fuse link, and means carried by said fuse tube and normally out of engagement with said lever for limiting the outward motion of said fuse tube to maintain contact between the upper contact of said fuse tube and the upper stationary contact.

v15. A fuse Iconstruction comprising a housing having stationary upper and lower contacts and having a lower support, a fuse tube and door assembly, said fuse tube having an upper contact normally engaging said upper stationary contact and having a lower contact normally engaging the lower stationary contact and including y, a spring pressed contact lever carried by said fuse tube, a lever pivoted on said support and pivotally connected to said fuse tube for guiding the lower end of said fuse tube and door assembly outwardly with reference to said housing while the upper end of said fuse tubevand door assembly remains in close proximity to said housing, said spring pressed contact lever remaining in contact with said lower stationary Contact for 4a material portion of the movement of the lower end of said fuse tube and door assembly outwardly and moving away from said lower stationary contact upon completion of the outward mo- 

